Some people say you should do your cardio first thing in the morning, before eating your breakfast. Others say you should do it in the afternoon for a boost of energy or even in the evening. But is there a right or wrong when it comes to doing aerobic exercise? Is one option better than the other or downright wrong and harmful?

But first, let’s define cardio. 

Cardio comes from cardiovascular and it refers to aerobic exercises that are meant to increase your heart rate. Aerobic stands for “with oxygen”, meaning that your body produces energy through the use of oxygen. A higher heart rate allows more oxygen to reach your cells that will use it to produce energy. Aerobic exercises can be done for longer periods of time than anaerobic ones. Examples of aerobic exercises are running, cycling, swimming, walking, hike, and more. 

So when should we do these activities? It generally depends on our goals. 

Doing fasted cardio in the morning

While the discussion on whether fasted cardio promotes weight loss is still ongoing, many people promote this practice. Doing cardio first thing in the morning, before having breakfast, appears to promote weight loss. 

The morning is usually the time of the day when our blood sugar levels are lower due to a long time since the last meal. Any sugar we didn’t need for energy production has already been stored in our fat cells with the help of the insulin hormone. With both sugar and insulin levels down, our body will use the fat stored in our cells to produce energy. Therefore, fasted cardio is said to promote weight loss by using fat rather than sugar for energy. 

If you are looking to lose weight and have enough motivation and time in the morning, fasted cardio can be a good option.

Doing cardio in the afternoon

Another option is to do cardio in the afternoon. This is the time of the day when many people notice their energy levels lower therefore doing some aerobic exercise can help get energized. 

Aerobic exercises increase your heart rate and oxygen levels and they release endorphins, increasing your overall energy levels. The ideal time is somewhere in the mid-afternoon, a few hours after lunch.

Doing cardio in the afternoon may be more challenging for most people depending on their work hours. But if your schedule allows it, doing a half an hour brisk walk or jogging in the afternoon can be a good idea for an energy boost.

Doing cardio in the evening

For many people, exercising in the morning or during the day is just not feasible. That leaves us the evening. But when exactly in the evening is it ideal to exercise? 

Generally speaking, you should avoid high-intensity exercise right after going to bed. Ideally, you should workout around one hour before dinner but after a light snack to give you some energy. 

Evening exercise has been shown to improve relaxation and sleep quality. You’ll likely fall asleep faster when doing some aerobic exercise in the evening. 

What is the best time for cardio?

The simple answer is the time that works for you. Aerobic exercise has many health benefits no matter the time of the day you do it. 

As long as you avoid running right after a big meal or right before bed, you’ll be good to go. Find the time that works best for you depending on your schedule and on your energy levels. If you find it hard to jog in the morning before breakfast, don’t. Exercise shouldn’t be a choir so do it at the time of the day that you’ll get the most benefits from it.